Issue/Question: Does the length of each run of speaker wire need to be the same for the speakers they are going to? To put it another way, does the speaker wire length for the left-rear speaker need to be the same length as the wire for the right-rear (same sort of Q for the fronts)? It occurred to me that if the wire lengths were different for the right and left rears that it might result in some sort of delay or imbalance when the receiver sends the audio info. I don't know much about the specifics of how the audio signal travels, so not even sure this is possible...

As long as the lengths aren't too far apart, it shouldn't matter, You won't get a delay since electricity is really really fast. You may get an impedance mismatch if the lengths are very different. More likely to be an issue with thin speaker wire.

Just to put some numbers on it:
if you had one 100 foot wire and one 1 foot wire, the wave propagation delay would be around 0.0001ms (a tenth of a nanosecond). For comparison, that's the same amount of delay that would be introduced by the speed of sound if the speakers were different distances from the listener by 0.001 inches. For a 1ms delay, which is generally well below what anyone would notice, you'd need a wire that was 186 miles long.